Louis Dionne f6ba9850c0 [libc++abi] Use std::abort() instead of std::terminate() on failure to allocate ... Inside the Itanium demangler, we would previously call std::terminate() after failing to (re)allocate. However, programs are free to install a custom terminate_handler which does non-trivial things. In fact, by default libc++abi itself installs a demangling_terminate_handler() which tries to demangle the currently active exception before aborting the program. In case of an out-of-memory exception caused by the system truly having no more memory (as opposed to attempting to allocate INT_MAX just once), we will end up trying to demangle the exception, failing to do so because we can't grow the OutputBuffer inside ItaniumDemangle.h, and then calling std::terminate() there. That will call the demangling_terminate_handler(), which will then start this loop again. We eventually end up crashing due to a stack overflow. To fix this problem, this patch calls std::abort() directly from the demangler instead of going through std::terminate(). After all, calling std::abort() is the default behavior for std::terminate() according to the Standard, so this behavior is definitely valid. The downside of this approach is that in case of a "true" out-of-memory condition: 1. the program will throw an exception 2. std::terminate() will be called if uncaught 3. demangling_terminate_handler() will be called and will fail 4. abort() will be called We'll end up aborting the program without mentioning the cause, which normally looks like: terminating due to uncaught exception of type <TYPE>: <what()-MESSAGE> Another option would be to properly handle failure-to-allocate inside ItaniumDemangle.h and to propagate something like an error code or a std::expected to the caller of all functions in the demangler that can allocate. Then, we could make sure that __cxa_demangle returns nullptr when it fails to demangle the input due to any error, as it is supposed to (but today "true" out-of-memory conditions are not handled properly). The demangling_terminate_handler() would then see that __cxa_demangle failed to do its job and would still print the appropriate message, simply using the non-demangled exception type. However, this is akin to a partial rewrite of the demangler code since a large number of functions would now have to return a std::expected to account for out-of-memory conditions. Using exceptions would be a lot simpler in terms of code changes and would achieve the same result, however the demangler can't use exceptions because it is used inside LLVM and libc++abi implements the exception runtime anyway (so while it might be possible to use them in that context, I'd argue we'd only be playing with fire). rdar://110767664 Differential Revision: https://reviews.llvm.org/D155598		2023-08-31 14:58:08 -04:00
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src	[libc++abi] Use std::abort() instead of std::terminate() on failure to allocate	2023-08-31 14:58:08 -04:00
test	[libc++] Fix problems with GCC 13 and switch to it in the CI	2023-08-14 16:54:50 -07:00
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CMakeLists.txt	[libc++] Fix a few incorrect CMake configuration options	2023-08-17 09:43:09 -04:00
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